1. Field of the Invention
This invention relates to catalysts characterized by their method of preparation and to their use in processes for hydroconverting carbonaceous materials such as hydrocarbonaceous oils and coal.
2. Description of Information Disclosures
Slurry hydroconversion processes utilizing a catalyst prepared in a hydrocarbon oil from a thermally decomposable or oil soluble metal compound catalyst precursor including chromium compounds are known. See, for example, U.S. Pat. No. 4,226,742 and 4,244,839.
It is also known to use such catalysts in hydroconversion processes (i.e., coal liquefaction) in which coal particles are slurried in a hydrocarbonaceous material. See, for example, U.S. Pat. No. 4,077,867.
The term "hydroconversion" with reference to a hydrocarbonaceous oil is used herein to designate a catalytic process conducted in the presence of hydrogen in which at least a portion of the heavy constituents of the oil is converted to lower boiling hydrocarbon products while it may simultaneously reduce the concentration of nitrogeneous compounds, sulfur compounds and metallic constituents.
The term "hydroconversion" with reference to coal is used herein to designate a catalytic process conducted in the presence of hydrogen wherein coal is converted to normally liquid hydrocarbon products.
All boiling points referred to herein are atmospheric pressure equivalent boiling points unless otherwise specified.
It has now been found that the addition of an aliphatic polyhydroxy compound to an aqueous solution of chromic acid (CrO.sub.3) to form a catalyst precursor mixture which is subsequently added to a hydrocarbon medium and converted to a solid catalyst under certain conditions in the hydrocarbon medium will produce a novel catalyst that will yield less coke when used in hydroconversion processes.